Smartwatches with oxygen level measurement

Pulse oximeter (oxygen)

— a sensor that determines the saturation of the blood with oxygen; at the same time, the measurement is carried out by a non-invasive method — without punctures and other damage to the skin. Like most "medical" sensors in wearable gadgets, it is not accurate and is not a full-fledged medical device, but it is quite capable of responding to a critical decrease in the level of oxygen in the blood. It is believed that the presence of a pulse oximeter is relevant primarily for certain diseases, when saturation may decrease due to the disease itself or the specifics of the treatment being taken. However, this feature can also be useful for quite healthy users who often travel at high altitudes — primarily climbers and aeronauts.